Add code actions prefix UI

Not only does this show a diff of the selected code action before you
apply it, it uses Telescope for display and selection of the desired
code action.

lua/plugins/completions.lua

@@ -13,6 +13,9 @@ return {
     'hrsh7th/cmp-cmdline',  -- Source for command-line
     'hrsh7th/nvim-cmp',     -- Completion engine combines and use the above
 
+    -- LSP UI plugins
+    'aznhe21/actions-preview.nvim',
+
     -- Lue vim module support in lua language server
     'folke/neodev.nvim',
 
@@ -108,7 +111,8 @@ return {
         -- coc.nvim was being weird about it
 
         -- Fixit mapping, or close enough, actually any code action
-        vim.keymap.set('n', '<leader>fi', vim.lsp.buf.code_action, opts)
+        vim.keymap.set('n', '<leader>fi',
+          require("actions-preview").code_actions, opts)
 
         -- Goto definition mapping
         vim.keymap.set('n', 'gd', vim.lsp.buf.definition, opts)